The dsh Terrain Building Test

[dshall]

Scott:

I understand that you can do terrain, Gerrry can do terrain, and now I can do terrain (somewhat)

the question is you are advocating ALWAYS setting the "pad elevation" to 0" and that doesn't work when trying to match a survey with sea level contours

try the Denver challenge

Lew

I will post the Denver challenge as soon as it is done cooking. Yes, I always advocate setting the pad elevation at "0", and you understand why when you watch the Denver Challenge.

[gteacher]

On the off chance that Chief is still reading these posts: I would not want them to get the impression all of us are dissatisfied with the way chief is calculating elevation pad height or that auto-calc is not needed.

The present method works fine for builders and owners who need a local reference. Sea level data is needed occasionally for flood and location submittals.

Scott's method just resets the elevation regions by the same bias, which you could do individually anyway - 6 vs 1/2 dozen.

For MY vote -Chief don't change anything -- except:

1. For auto-calc on- add a field for foundation top offset ( Code is 4-6" - I use 8-16")

2. For auto-calc on/off - add a 0" elevation offset to add x" to all elevation data and if this is used allow a option to change colors of elevation text to indicate sea level. As an alternate allow a elevation setting of a local marker's elevation height which would bias all elevation data. Provide a unique location symbol for that marker to indicate abs elevation and/or that all plan elevation terrain data is subsequently referenced to that marker. The local marker concept would eliminate the confusion for new users of terrain zero vs floor zero.

3. Allow input of surveyor shot point data in TEXT format (OR excel) to establish elevation points, lines, regions,plan lines, etc.

Other than that -- Please keep everything the same.

Oh -- Fix the update problem.

[Glenn Woodward]

D. Scott,

You missed a very important think in your latest video.
When you did a simple building on a flat terrain with no elevation data, you opened the Terrain dbx (Auto Calculate still checked) and the Pad Elevation box returned zero.
Well, this is wrong - as Gerry pointed out, the box has not updated.
Build the terrain and have another look.
Mine now says 200mm - which is correct according to "the formula", meaning that Chiefs zero floor level is 200mm above the terrain - THE TERRAIN BEING ZERO and Chiefs zero floor level being 200mm above a flat terrain at zero..

As far as I can see there is one thing that needs to be changed:
Get rid of the words "Pad Elevation" and call it "Chiefs Zero Floor Level" or similar.

This is the most important bit:
If you always think of "Pad Elevation" as what you want Chiefs zero floor level to be, you won't have any problems with relative, absolute, auto calculate, no auto calculate, etc, etc. - it will always work.

Try a few exercises using this method and you will see how easy it is.
This is the thought process I use and how I use Pad Elevation, and it always works easily.

If others want a way to change all the levels once specific site data is available, then this may be another improvement, but it's not important to me and is another issue.

[louis]

I do the same Glen and always have and I have taught it this way as well. Thanks for the post.

[Glenn Woodward]

Louis,

If Chief made that one little change to the nomenclature of Pad Elevation and everyone started thinking that way, we wouldn't be having this discussion - because there would be no confusion!

[perryh]

The 6" added to the auto pad elev. is still wrong.

[dshall]

For over 4 years I have always set the PAD ELEVATION at zero. For the last 4 years I have always added a terrain region to then modify the PAD ELEVATION ht. It works great.... until I want the contours to read as my topo from surveyor, something I rarely get until after my house and pad has been built. Which now means I need to change the pad elevation and the terrain regions accordingly. I get that, I get that, I get that. No problem, easy peasy.

Glenn, you want to start building your new project but you do not have a topo, what do you set your pad elevation at? Probably zero. You still do not have a topo yet you want to drop your pad down below the f.f., how do you do it? Probably terrain regions. You now have your model built and your terrain built and now the surveyor gives you the actual topo map, how do you update your model.

The explanation for this line of thinking, and I have said this before, 97% of the time my model and building pad is built before I get the topo. Should I get the topo prior to beginning model, maybe, but it rarely happens.

You do not need to answer these questions, I am assuming you do it the same way I do.

EDIT: Glenn, I retract the statement that you probably do it the same way.... we get to the same place but take different routes. 99.7% of the time I initially build my building pad relative to house and then adjust later if I get a topo map.

[Glenn Woodward]

For over 4 years I have always set the PAD ELEVATION at zero. For the last 4 years I have always added a terrain region to then modify the PAD ELEVATION ht. It works great.... until I want the contours to read as my topo from surveyor, something I rarely get until after my house and pad has been built. Which now means I need to change the pad elevation and the terrain regions accordingly. I get that, I get that, I get that. No problem, easy peasy.

Glenn, you want to start building your new project but you do not have a topo, what do you set your pad elevation at? Probably zero. You still do not have a topo yet you want to drop your pad down below the f.f., how do you do it? Probably terrain regions. You now have your model built and your terrain built and now the surveyor gives you the actual topo map, how do you update your model.

The explanation for this line of thinking, and I have said this before, 97% of the time my model and building pad is built before I get the topo. Should I get the topo prior to beginning model, maybe, but it rarely happens.


You do not need to answer these questions, I am assuming you do it the same way I do.

D.Scott,

It seems I do need to answer these questions because I thik you are assuming incorrectly.

When I start building my model and place a flat terrain (lets forget about using the Pad word, because I don't know what that means) I set the Pad Elevation to about 12" - because I want my Chief zero floor level to be 12" above a zero level flat terrain. If I set my Pad Elevation at zero - it is level with my floor - I don't want that - that's stupid!

If I now want to drop my terrain down 12", I make my Pad Elevation (Chiefs zero floor level) 24". The distance between my terrain and Chiefs zero floor level is 24" - simple. I don't use terain regions as you suggest.

Now, if I get a topo from my surveyor that goes from 100' to 200' and I want my floor level at 150', it's easy.
I enter my topo info and then set the Pad Elevation (Chiefs zero floor level) to 150'.
How easy is that!!!

I don't care if it's relative, absolute, sea level, blah, blah, blah.

Edit:
I just saw your Edit.
Of course we get to the same end point - it's just that my way is the esiest and most logical!

[gteacher]

Scott’s Terrain

Scott’s procedure sets the terrain reference point under the floor structure at 0”with a local region (His local marker point). The local region establishes the build pad and any needed landscaping in case drainage is a consideration. This assumes that the local site survey data will reference to that point, which it rarely does. Usually, it’s at some local corner, which means that all elevations planes would have to be multiplied by the relationship of actual marker height vs the building zero height (bias). An easy calculation, but a source of error.

Scott also requires that a surveyor will review his plan at some point and determine sea elevation at the building footprint. An hour or two of work, but something an Owner may not want to pay for. More likely a local marker is near in which the owner is aware. As in road center height, or top of sewage line height, etc. Using a local marker, not necessarily at the pad location, would require that the terrain zero point be translated to that location causing another bias(s) if building pad elevation is to be maintained at zero. Another source of error.

Finally, in not using auto-calc, you must determine “center point” terrain height yourself and do the math. All are 2minute cals, but another source.

Scott’s use of terrain regions for a bias source is advantageous, but regions are not always possible to use. Particularly, in W PA and W VA. If you cannot use regions, you multiply the number and type of data sources to keep track of.

In any event, even with this method, turning on auto-cal simplifies everything and eliminates “forgetfulness”. The only problem with auto-cal is Chief’s use of a fixed foundation bias of 6”. This simple limitation seems to be the reason for the confusion and why people will not use a valuable tool. Chief saved one input text box but effectively wasted hundreds of hours of programming on this – penny wise.

But this problem can be solved by just waiting until the end of the design, than open the DBX Pad Elevation, and add whatever to the reading. I agree that Scott’s method is viable, but with the various applied practical conversions and cross checks, not more so then anything else.

[lbuttery]

Glenn:

how would you do the Denver challenge in post #68 ???

I think your last reply covers it but I'm not sure ???

I thought Scott was going to do a video for this challenge ???

Lew

[Glenn Woodward]

Scott:

you are correct, just as Glenn pointed out - most chiefers think of the house first
then later want to set the terrain relative to the house

unfortunately, that's not the way chief thinks at this time

you mention setting the pad elevation to 20'
in chief that means 20' above sea level whereas you are probably thinking 20' above "terrain"

consider building a house in Denver the "mile high city"
there is lots of flat land there yet the sea level elevation is 5000'

thus when you enter a value into the "pad elevation" you should be entering 5020'

the up slope contours would then be 5021,5022, etc
the down slope contours would then be 5019,5018 etc

this is important when trying to match a survey's contours

I do think it would be nice if chief would allow us to display the contours in "relative" terms
of the relationship between the house and the terrain

even tho we enter the values in absolute terms in relation to sea level

Lew

Lew,

I would do it exactly as you describe - where is the challenge? Where is the confusion?

Enter topo information directly off the survey based on sea levels.

Enter the Pad Elevation as 5020' - ah, which just happens to be the elevation you want Chiefs zero floor level to be! Which is what I have been saying all along - Pad Elevation should read as "Chiefs Zero Floor Level".

I don't understand why you would want to change levels relative to the building floor level. The surveyor has provided all the topo information relative to sea level - that's what you would use to set the building heights out - that's what floor level should relate to.
Why would you confuse things by trying to convert all the levels relative to floor level being zero - I don't understand why anyone would want to do this!!!

[lbuttery]

Why would you confuse things by trying to convert all the levels relative to floor level being zero - I don't understand why anyone would want to do this!!!

Glenn:

because I might want to know that from the front door to the street the elevation drops 8'

if the contours show as absolute sea level value as 5019 down to 5011
I have to do the math - not hard math but in different scenarios it might be harder

looking at contours that are -1, -2 ... -8 just makes it clearer/quicker

also the absolute sea level elevations don't show the minus sign so it takes
looking at a few contours to confirm that the terrain is sloping down

with relative values that show the minus sign it instantly clear that they slope down

then consider if they start to slope up again - still minus for awhile but the numbers are growing smaller until they go positive

all in all just a clearer/quicker way of viewing the data

yet it would also be displayable in the absolute sea level values - if needed

we should have the choice of which way to view the same data

thanks for confirming that your method works with sea level data as well

I think from now on I will skip the auto-calc method
unless I am required to show the relative changes in elevation

that is until chief adds this improvement

Lew

[dshall]

Thanks Lew, absolutely correct. Because of the method I use the terrain is relative to the finish floor elev. This facilitates designing retaining walls etc.

[gteacher]

IF yous Guy want to know what the confusion is here you might want to look at Scotts video in his Post # 71. I just did. Scott's video in which he was critical of Lew's plan, perfectly shows that Lew is using Chief correctly and was correct in the video even though Scott did not realize it. Scott was simply insisting that Lew do something which you normally would not do. Set terrain at bottom of f.f wood structure.

Chief made the correct adjustment when Scott changed elevation - my point and Lews

Scott, there is a difference between setting elevation for a monoslab and a wood floor w/foundation. Also, with a monoslab, Terain is set at the bottom of the slab, not the footer.

Lew: I don't think I have to make another video, I couldn't improve on Scotts.

Auto-calc works perfectly well. Another feature, seldom used because it's limited and confusing. OOPS --- said that before.

[lbuttery]

my point and Lews


Gerry:

for the record I was trying to comply with Scott's challenge with auto-calc off and with auto-calc on

I made a mistake with the auto-calc on plan which is the one Scott used in his video

so my "getting it right" was by accident


Lew